EFFECTS OF POULTRY MANURE AND UREA APPLICATIONS ON SOIL ORGANIC MATTER AND PHOSPHOROUS UPTAKE BY Amaranthus cruentus IN SULPHUR-AMELIORATED SALINE SOILS OF DUTSE, JIGAWA STATE, NIGERIA

This study evaluated the effects of poultry manure and urea on soil organic matter and phosphorus uptake by Amaranthus cruentus sulphur-ameliorated saline soils of Dutse, Jigawa state of northern Nigeria. Saline soil samples were collected from the Teaching and Research Farm of the Federal University, Dutse. These soil samples were treated with elemental sulphur (2.0 g per 50 g soil) to reduce salinity and potted in a factorial completely randomized design with four treatments (with/without poultry manure and urea) and three replicates. Plant growth parameters (leaf count, height, dry matter) were measured at 3, 6 and 9 weeks after sowing. Results indicated that treatments without poultry and urea applications performed better due to sulphur salinity mitigation. However, combined poultry manure and urea application significantly increased phosphorus uptake (2.10 mg/pot), while poultry manure alone enhanced soil organic carbon (23.40 g/kg) and organic matter (40.25 g/kg). The study demonstrated that sulphur amendment improves saline soils, with synergistic nutrient management further boosting crop productivity and soil health. To improve nutrient availability in reclaimed saline soils, the application of organic amendments (such as manure and crop residues) along with sulphur and phosphorous based fertilizers is essential. For optimal soil organic carbon (SOC) improvement, a combined approach, using poultry manure alongside crop residues or adopting conservation tillage practices is highly recommended.